The present invention relates to the field of electronic devices, and more particularly, to electronic signal processors and related methods.
Signal processing systems are commonly used in a wide variety of applications. For example, many electronic devices use signal processors to detect and interpret various input signals, such as from a remote control, and provide an appropriate response based upon the signals. Signal processors may also be used to interpret radio frequency (RF) signals from a radar antenna to detect the location of aircraft, for example. Another example may include using a signal processor to interpret vibration signals from a seismometer or geophone to determine the location of various geological strata and formations in seismic exploration, for example.
An example of a signal processing system for detecting moving targets is disclosed in U.S. Pat. No. 4,368,460 to Clinard et al. entitled xe2x80x9cDual Mode Moving Target Sensor.xe2x80x9d This patent discloses a dual mode sensor having a seismic channel and an RF channel with a logic circuit for recognizing both channels. The seismic channel detects disturbances with a geophone and determines spacing and impulse density. The RF channel radiates electromagnetic energy and detects impedance changes in an oscillator circuit driving the antenna when the target is in the vicinity.
U.S. Pat. No. 4,944,036 to Hyatt entitled xe2x80x9cSignature Filter Systemxe2x80x9d discloses a filtering system for acquiring and processing signals using a sampled filter for signal separation and signal enhancement. For example, the filtering system may be configured for use with geophones when used in a geophysical application, hydrophones when used in sonar applications, and radar receivers, such as phased array antennas, for radar applications.
One potential drawback of such prior art devices is that they may not accommodate enough signal types to provide a complete interpretation in a given environment. For example, it may be necessary in some applications to processes acoustic and/or optical signals to correctly detect a moving target, which would not otherwise be possible with the target sensor disclosed in the Clinard et al. patent. Also, while the filter system disclosed in the Hyatt patent may be configured to process different signal types, this patent does not provide a way to combine such functionality within a single device. Thus, it may be cumbersome as well as expensive to use multiple prior art devices to provide adequate signal processing capabilities for certain applications.
In view of the foregoing background, it is therefore an object of the invention to provide a multiple input-type and multiple signal processing-type device and related methods.
This and other objects, features, and advantages in accordance with the present invention are provided by a multiple input-type and multiple signal processing-type device including an input stage for receiving a plurality of different analog signal types, a down-converter for downwardly converting first signal types to a desired processing frequency range, and an up-converter for upwardly converting second signal types to the desired processing frequency range. Furthermore, the device may include an analog-to-digital converter (ADC) for converting analog signals at the desired processing frequency range into digital signals, a time domain signal processing section connected to the ADC for performing time domain signal processing on the digital signals, and a frequency domain signal processing section connected to the ADC for performing frequency domain signal processing on the digital signals. A digital down converter (DDC) for special processing may also be included upstream from the time and/or frequency domain signal processing sections.
More particularly, the device may advantageously include a user selector input for permitting a user to selectively activate one of the down-converter or up-converter, and to selectively activate one of the time domain or frequency domain signal processing sections. Additionally, a signal recognition processor may be included for performing signal recognition to determine whether to selectively activate the down-converter or up-converter, and to determine whether to selectively activate the time domain or frequency domain signal processing sections.
The time domain signal processing section may include a convolution module for performing pattern recognition on the digital signals and/or a pulse threshold crossing module for performing waveform detection on the digital signals. Further, the frequency domain signal processing section may include a convolution module for performing pattern recognition on the digital signals and/or a spectral threshold crossing module for performing waveform detection on the digital signals.
Moreover, the spectral threshold crossing module may include a constant false alarm rate (CFAR) module, a magnitude calculation module upstream from the CFAR module, and a DC term or interference signal elimination module upstream from the magnitude calculation module. The spectral threshold crossing module may also include at least one of a fast Fourier transform (FFT) module and an inverse FFT (IFFT) module.
Additionally, the multiple input-type and multiple signal processing-type device may include at least one filter coupling the analog signals at the desired processing frequency to the ADC. Also, the plurality of signal types may include at least two of optical signals, radio frequency (RF) signals, seismic signals, and acoustic signals.
A method aspect of the invention is for processing multiple signals having different signal types and may include providing a multiple input-type and multiple signal processing-type device as described above. The method may further include configuring the multiple input-type and multiple signal processing-type device to permit a user to selectively activate one of the down-converter or up-converter, and configuring the multiple input-type and multiple signal processing-type device to permit the user to selectively activate one of the time domain or frequency domain signal processing sections.
Another method aspect of the invention is for processing multiple signals having different signal types and may include providing a multiple input-type and multiple signal processing-type device as described above. The method may further include using a signal recognition processor to perform signal recognition to determine whether to selectively activate the down-converter or up-converter, and to determine whether to selectively activate the time domain or frequency domain signal processing sections.